[revel]

I don't think that the problem is that JavaScript may or may not have this feature, it's not even that the language is large and all-encompassing; it's that mixing and matching features is highly appealing and very rarely works out well in practice.

JavaScript is not really a single language built around a single specific style or set of needs any more. In this day and age it's an amalgamation of different techniques and styles. You've got classic inheritance and composition for your OOP crowd; you've got your map and reduce for your functional crowd; you've even got your observables for your reactive crowd.

This is all well and good, but I've found that it's hard to write some practical code that blends styles. At some point it's tempting to start adding types, generics and dependency management into a functional project, but it's my experience that this blending ends up getting in the way of itself. Similar story for wanting to do things like having a service that listens to queues in an async way with sync rest APIs. It seems like having a common set of middleware would make it easy to support both layers; however this is easier said than done. These things sort of work but it feels deeply unsatisfying, requiring constant switching between observable and async/await styles with error handling being a constant concern.